221647213 has 2 divisors, whose sum is σ = 221647214. Its totient is φ = 221647212.

The previous prime is 221647171. The next prime is 221647273. The reversal of 221647213 is 312746122.

221647213 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 215561124 + 6086089 = 14682^2 + 2467^2 .

It is a cyclic number.

It is not a de Polignac number, because 221647213 - 2¹³ = 221639021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221647273) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110823606 + 110823607.

It is an arithmetic number, because the mean of its divisors is an integer number (110823607).

Almost surely, 2^221647213 is an apocalyptic number.

It is an amenable number.

221647213 is a deficient number, since it is larger than the sum of its proper divisors (1).

221647213 is an equidigital number, since it uses as much as digits as its factorization.

221647213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 28.

The square root of 221647213 is about 14887.8209621153. The cubic root of 221647213 is about 605.1839824755.

The spelling of 221647213 in words is "two hundred twenty-one million, six hundred forty-seven thousand, two hundred thirteen".